Heat sealing machine for a packaging system

ABSTRACT

In a system for discretely packaging liquid or solid medication or other substances comprising a compartmented tray ( 10 ) with a perforated sealed sheet ( 21 ) attached thereto and individual removable pots ( 17 ) to which the sealed sheet is also sealed, a heat sealing machine to cause the sheet ( 21 ) to be sealed to the individual pots ( 17 ) and to the tray ( 10 ) whist simultaneously folding and sealing a front flap ( 29 ) of the film ( 21 ) to an end face ( 15 ) of the tray, comprising a heated plate ( 30 ) and a spring loaded pressure plate ( 32 ) with a supplementary heated member ( 36 ) and adjustable spot- sealing pins ( 37 ) pivotally mounted on the machine such that as the heated plate ( 30 ) seals the top of the film ( 21 ) so the pins ( 37 ) fold the front flap ( 29 ) of the film ( 21 ) down over the end of the tray and seal it thereto. Thus, the film ( 21 ) is sealed to the tray on two planes substantially simultaneously.

This invention relates to a system for discretely packaging a plurality of quantities of one or more fluid or solid substances.

Particularly, although not exclusively, the system has been devised to meet the needs of patients and carers in the safe, accurate and convenient monitored dispensing of medication both in liquid and solid forms. Liquid medication, apart from the use of individual sachets or blisters, is currently supplied to the patient or carer in large containers from which individual doses are dispensed, usually into a measuring spoon from which the patient takes the medicine.

It is of the utmost importance that a patient should take an accurate dose of the correct medicine and that there should be no risk of confusion or of cross-contamination between patients should a large bottle of medication be used, perhaps improperly, to dispense the medication to different patients. Such a system is described and claimed in our co-pending patent application number GB 0719991.2 in which there is provided a container for discretely packaging a plurality of quantities of one or more fluid or solid substances, and comprising a tray having individual spaced compartments and a plurality of vessels individually removably received within the respective compartments and adapted to contain the substances to be packaged, and a sealed film releasably to retain the vessels in the compartments prior to intended use, the film sealingly retaining the substances in the vessels prior to their intended use. The vessels are individual pots removably received within the compartmented tray, and the sealed film is perforated around the individual pots so that they may be removed from the tray independently when required. Thus, the film must be sealed around each pot to ensure that the pots, when removed, remain sealed until required for use.

The film may be printed with data representing the contents of the vessels, their intended dosage, and, for example, a patient's details.

The entire tray may be housed as one of several such trays, stacked one above another, in a cabinet or trolley for use, for example, in a nursing home, and it is intended that the tray should have an end face to which the film is also sealed to reveal data pertaining to the contents of the entire tray.

While heat sealing of such a film to the tray along its upper and horizontal plane in a single operation is straightforward, nevertheless it is necessary, substantially simultaneously, to seal the end region of the film to the substantially vertical end face of the tray.

It is an object of the present invention to provide a heat sealing machine which will achieve the simultaneous sealing of the film to the upper and end faces of the tray.

According to the present invention there is provided a heat sealing machine for applying heat at predetermined positions on a heat sealable film placed over a compartmented tray to seal the film to the tray on two planes, one substantially normal to the other, the machine comprising a heated plate adapted to bear upon a heat sealable film superimposed on a first plane over a compartmented tray, a spring loaded pressure plate adapted to bear upon the heated plate, a supplementary heated member movable with respect to the heated plate and having a pressure member adapted to bear against the heat sealable film to become superimposed over the surface of the compartmented tray on a second plane.

The pressure plate and the supplementary heated member may becoming interengaged when the pressure plate bears against the heated plate.

The heated plate may include shaped contact dies to cause the film to be sealed to the tray peripherally around each compartment of the tray.

The heated plate may include contact dies to cause the film to be sealed between the compartments of the tray.

The supplementary heated member may be pivotally mounted with respect to the heated plate and moved into a sealing position by the pressure plate when it bears upon the heated plate.

The supplementary heated member may be spring loaded thus to assume a non-sealing condition until engaged by the pressure plate.

The supplementary heated member may have adjustable heating pins which cause the film to be superimposed over an end face of the tray and spot-sealed thereto.

Movement of the pressure plate may cause the film to be sealed around and between the compartments, and spot-sealed to the end face of the tray substantially simultaneously.

Control means may be provided to enable the temperature of and/or the pressure applied to the heated plate, and/or the duration of sealing contact to be determined.

Means may be provided to introduce a tray and film into the machine and to remove the tray with the sealed film from the machine automatically.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 is an exploded perspective view of a container of a system for discretely packaging a plurality of quantities of one or more fluid or solid substances;

FIG. 2 is a schematic side elevation of a heat sealing machine made in accordance with the invention for use in connection with the container of FIG. 1;

FIG. 3 is a similar view of the heat sealing machine in a first phase of operation;

FIG. 4 is a similar view of the heat sealing machine in a second phase of operation;

FIG. 5 illustrates, on the container of FIG. 1, a sealing mode created by the heat sealing machine, and

FIG. 6 is a perspective view of a container clamping assembly.

Referring to FIG. 1, a container to be sealed comprises a tray generally indicated at 10 of a plastics material and formed to define side walls 11 and an array of individual, preformed, side-by-side compartments 12 each having a flexible base 13 and a common upper platform 14 extending across the tray 10 between the compartments 12. A front wall 15 provides a surface, as will be described, for the display of data concerning the contents of the tray.

Located within each compartment 12 is a vessel in the form of an individual pot 17 for containment of a substance to be packaged. Each pot 17 has an upper flange 18 which when the pot is located in the tray rests upon and flush with the platform 14. The pots may be of the same material as the tray.

The shape of the recess defined within each pot 17 is such as to have a curved upper rim 19 at least at one side. Opposite the curved rim 19 in each pot is a straight edge 20. The walls of each pot also conform to the shape of the upper rim.

For preference, each pot 17 is of such a size as to be an interference fit within its compartment, which is of complementary shape and size.

With all of the pots 17 in place a pharmacist may place the appropriate medication in each pot either by using a measured pipette for liquid medication or by placing tablets or capsules into the pots for solid medication.

To complete the container a flexible sheet 21 of a non-permeable heat sealable material having perforations 22 is placed over the filled tray and sealed toit, as will be described. The perforations 22 coincide with the outer peripheries of the pots 17 thus to define individual sealed films 23, one across each pot. The sheet 21 is sealed to the platform 14 and around each individual pot flange 18, as will be described.

With the sheet in place the pots can be removed individually by pushing a pot upwards at the base 13 in the associated compartment thus breaking the perforation in the sheet 21 while maintaining the integrity of the sealed film 23. Once the pot is removed the sealed film 23 remaining on the flange 18 can be peeled off when required to open the pot whereupon the medication can be taken. The curved rim 19 of each pot facilitates the taking of liquid medication. The regions of the flange 18 either side of the curved rim will have sufficient flexibility that they can be deformed to assist in release of the individual sealed film 23.

In this manner therefore individual pots can be removed whilst the remainder are retained and sealed on the tray 10. The individual films 23 may be printed, for example, with the time and date and the contents of the associated pot while a front flap 29 of the sheet 21 can be printed with information pertaining to the contents of the entire tray.

Referring now to FIGS. 2 to 5, in order to effect a seal of the film 21 to the tray 10 with its pots 17 contained therein, the entire assembly of tray, pots and superimposed film is introduced into a heat sealing machine as shown schematically in FIG. 2. The machine comprises a heated plate 30 having on its lower face a plurality of dies 31 shaped to determine the areas in which the film is sealed to the tray peripherally around each pot 17 and between the pots, as will be shown.

The machine further comprises a pressure plate 32 which is spring loaded at 33 to bear down on the heated plate 30, a pneumatic cylinder 34 or the like serving to actuate the pressure plate 32 when required.

Pivotally mounted at 35 on one end of the heating plate 30 is a supplementary heated member 36 having a row of adjustable sealing pins 37 mounted thereon. A spring 38 normally retains the supplementary heated member 36 in the position shown in FIG. 2.

The supplementary heated member 36 and the pressure plate 32 have complementary inclined faces 39 and 40 respectively for a purpose to be described.

FIG. 2 shows the heat sealing machine in a non-operative position with a tray 10 and film 21 placed in readiness for sealing. The tray is slightly recessed to form a well in which the film 21 sits, and has upstands 53 (see FIG. 6) which engage complementary registration notches in the edge of the film.

Referring now to FIG. 3, in a first phase of operation, pressure plate 32 and springs 33 are shown bearing down on the heating plate 30 whose dies 31 are in sealing contact with the film 21 to seal it to the pots 17 and tray 10.

With reference to FIG. 5, it will be seen that the dies create a line of sealing 41 around the top of each pot 17 to seal the film 21 to the individual pots around their flanges 18, and simultaneously to spot-seal, at 42, to the tray between the compartments.

As can be seen from FIG. 2, when the heating plate 30 descends, the adjustable sealing pins 37 of supplementary heated member 36 cause the front flap 29 of the film 21 to be folded over the front wall 15 of the tray 10.

Referring now to FIG. 4, in the second phase of operation of the sealing machine the supplementary heated member 36 is moved pivotally by the wedge effect of the coinciding faces 39 and 40 of the supplementary heated member 36 and the pressure plate 32 such that the adjustable heating pins 37 are forced against the front flap 29 of the film 21 to spot-seal it to the end face 15 of the tray 10. The sealing positions of the pins 37 are illustrated at 43 in FIG. 5.

Thus it can be seen that the film 21 is at least substantially simultaneously sealed against the upper horizontal face of the tray 10 and its vertical front wall 15.

Once the sealing action is completed the pressure plate 32 is retracted together with the heating plate 30 and the supplementary heated member 36 to resume their positions as illustrated in FIG. 2, whereupon the tray with its sealed film is automatically discharged from the machine. Introduction to and discharge from the machine of the tray is carried out automatically by an electrically, pneumatically or hydraulically operated drawer arrangement which delivers the trays smoothly into the sealing unit so as not to disturb any liquid contents of the pots 17, and clamps associated with the drawer arrangement ensure that the film 21 remains accurately in place over the tray. It is important that the film 21 shall not move out of register with the tray during its introduction to the machine.

Preferably, the pressure plate 32 descends with a single motion thus to effect substantially simultaneous sealing of the top and end of the film 21 thus to minimise the time taken for the tray to be sealed. The sealing process preferably requires no more than five seconds of heat application thus to minimise any adverse affect on the medication contained within the pots 17.

Referring now to FIG. 6, the drawer arrangement and clamps are illustrated according to one example. In the drawer arrangement the container 10 with its film 21 superimposed thereon, is placed on a platen 44 which is transported into the sealing machine and which includes a pair of side clamps 45 each with a pair of spaced lips 46 which hold the film 21 in place on the container 10. The clamps 45 are rotatable on shafts 47 journalled in the platen 44. A pair of links 48 pivotally connected to the shafts 47 by links 49 fixed to the shafts 47 are also pivotally attached to a lever 50 having, in this example, a handle 51. The lever 50 is pivotally connected to the platen 44 at 52 so that, in FIG. 6, if the handle and lever 50 are rotated in an anti-clockwise direction, this causes the clamps 45 to release the container 10 after the film 21 has been sealed thereto.

The lever 50 and handle 51 may be replaced by a rotatable knob on an axis at 52 in order to reduce the height of the assembly. Indeed, any alternative mechanism may be provided to cause the clamps 45 to retain the film 21 and container 10 during its introduction into the sealing machine, and to release the sealed container upon removal from the machine. The mechanism including the drawer and clamps may be operated manually or automatically, but affords smooth movement in operation in order to minimise the risk of dislodgement or spillage of the contents of the pots.

Control means are provided to enable the temperature of and/or the pressure applied to the heated plate, and/or the duration of sealing contact to be predetermined thus to ensure sealing without unduly heating of the tray and its contents. Thus, the user may manage and control the combination of heat, pressure and time of application of the process so that the strength with which the film 21 is welded to the pots 17 can be varied thus in turn to vary the ease with which the supplementary seals 23 may be peeled from the pots. The variable strength of weld also enables a level of child protection to be determined so that the supplementary seals may be peeled with sufficient ease by the patient but nevertheless represent a restriction to prevent a small child from easily removing the seal. The selection of weld strength is also of importance when producing sealed trays for elderly patients with chronic conditions such as arthritis, where the strength of the weld may be reduced accordingly.

The heat sealing machine made in accordance with the present invention includes a built-in compressor to provide compressed air to actuate the pneumatic cylinder 34 in order to move the pressure plate 32 to carry out the sealing operation.

The platen 44 on which the tray is placed and to provide a reaction for the pressure of the heating plate. To ensure complete uniformity of heat application the platen may include resilient means to ensure that the shaped dies of the heating plate make uniform pressurised contact with the film 21 throughout its upper surface. Thus, every weld created by the heating plate dies is of uniform strength.

It is not intended to limit the invention to the example described above, many variations being possible without departing from the scope of the invention as defined in the appended claims. For example, the individual adjustable pins 37 may be replaced by a single rail thus to cause a line-seal as opposed to spot-sealing of the front flap 29 of the film 21. Similarly, pivotal movement of the supplementary heated member 36 may be effected other than by the wedge action of complementary faces 39 and 40.

Sealing of the film 21 is effected by virtue of the thermoplastic properties of the film. Alternatively, the film may be coated with a heat-sensitive adhesive thus to be bonded to the tray upon the application of heat. 

1. A heat sealing machine for applying heat at predetermined positions on a heat sealable film placed over a compartmented tray to seal the film to the tray on two planes, one substantially normal to the other, the machine comprising a heated plate adapted to bear upon a heat sealable film superimposed on a first plane over a compartmented tray, a spring loaded pressure plate adapted to bear upon the heated plate, a supplementary heated member movable with respect to the heated plate and having a pressure member adapted to bear against the heat sealable film to become superimposed over the surface of the compartmented tray on a second plane.
 2. A heat sealing machine according to claim 1, wherein the pressure plate and the supplementary heated member become inter-engaged when the pressure plate bears against the heated plate.
 3. A heat sealing machine according to claim 1 wherein the heated plate includes shaped contact dies to cause the film to be sealed to the tray peripherally around each compartment of the tray.
 4. A heat sealing machine according to claim 1 wherein the heated plate includes contact dies to cause the film to be sealed between the compartments of the tray.
 5. A heat sealing machine according to claim 1 wherein the supplementary heated member is pivotally mounted with respect to the heated plate and moved into a sealing position by the pressure plate when it bears upon the heated plate.
 6. A heat sealing machine according to claim 1 wherein the supplementary heated member is spring loaded thus to assume a non-sealing condition until engaged by the pressure plate.
 7. A heat sealing machine according to claim 1 wherein the supplementary heated member has adjustable heated pins which cause the film to be superimposed over an end face of the tray and spot-sealed thereto.
 8. A heat sealing machine according to claim 1 wherein movement of the pressure plate causes the film to be sealed around and between the compartments, and spot-sealed to the end face of the tray, substantially simultaneously.
 9. A heat sealing machine according to claim 1 including control means to enable the temperature of and/or the pressure applied to the heated plate, and/or the duration of sealing contact to be predetermined.
 10. A heat sealing machine according to claim 1 including means to introduce a tray and film into the machine, and to remove the tray with the sealed film from the machine, automatically.
 11. A heat sealing machine according to claim 1, including clamping means to ensure that the heat sealable film shall be maintained correctly positioned with respect to the compartmented tray during its introduction into the machine.
 12. A heat sealing machine according to claim 1, including resilient means to ensure that the heated plate makes uniform pressurised contact with the heat sealable film on said first plane 